In the medical field, there has been a demand for cancer detection that can be performed easily in a short time by detection of whether or not a cancer cell is contained in collected blood. To this end, a trace amount of cancer cells needs to be detected, in a short time, from among a large amount of cells contained in blood.
Accordingly, a device for quickly, precisely, and low-invasively, at low cost, finding rare cells from among a population of an enormous number (e.g., one trillion or greater) of cells and analyzing the rare cells has been desired.
As a device for individually observing numerous cells, a flow cytometer has been conventionally known (see Patent Literature 1). Patent Literature 1 discloses a flow cytometer including a flow cell in which a sample liquid containing inspection objects flows as a laminar flow held at a prescribed flow rate, and including an imaging system which includes a high speed camera with a stroboscopic lamp and a burst CCD image sensor. In the flow cytometer disclosed in Patent Literature 1, inspection objects sequentially flowing in the flow cell in which the laminar flow has been formed are measured by means of the high speed camera, whereby the inspection objects are individually observed.